Two different (albeit related) issues.

A man should pay child support even if he doesn’t want the kids because he was willing participant of the intercourse that caused the foetus.

Abortion is about a woman’s right to her body. Even if you exclude rape, etc, and the woman had unprotected, consensual sex and got pregnant, she still had a right to decide about her own body. That’s a much bigger price to pay than a man dishing out cash. You can argue she should have used protection or whatever, but that’s kinda like saying people who smoke don’t deserve healthcare when they get sick. It’s her body, and regardless of what happened beforehand, a woman should have unreserved and unrestricted agency over her own body.

And of course there is also the issue of rape, health issues, etc that of course mean women should have the right to abortion. But it also can’t be limited to that because any woman, regardless of the context, had a right to abortion because it is her body.